1. Field of the Invention
The present invention relates a lens-fitted photo film unit and its manufacturing method, more particularly to the lens-fitted photo film unit that a letter or a mark formed on the unit body is selectively observable.
2. Explanations of the Prior Arts
A lens-fitted photo film unit with a simple taking mechanism has been produced so that they can enjoy taking pictures easily and anytime. The lens-fitted photo film unit is widely used due to its convenience that photography is immediately possible after purchase, and just asking a photo-lab for photofinishing is needed.
The lens-fitted photo film unit consists of a unit body with an unexposed photographic film preloaded, and an outer label surrounding at least a part of the unit body like a belt. The unit body consists of a main body with a simple taking mechanism attached, a front cover and a rear cover covering around the main body.
Recently, an illegal sale that a new photographic film is loaded in an empty lens-fitted photo film unit after removing an exposed photographic film has been done. So as to cope with such illegal film reloading, a name of a manufacturer, a letter of a brand, a mark or a trademark of a company indicating its origin is formed on the front cover or the rear cover. The letter and the mark are formed by making grooves or irregularities around its contour upon plastic molding.
The lens-fitted photo film unit is used as a gift for helping sales promotion or a present to customers. In such a case, it is preferable to add the name or the mark of the gift-providing company to the unit body on behalf of the manufacturer. It is necessary for this purpose to prepare an injection mold in which the letter of the company are formed. In case of small production, however, manufacturing cost is remarkably raised as molding is expensive. Accordingly it is used a replaceable core or telescopic on which the name of the gift-providing company is engraved, so as to be fitted into a hollow part of the molding (See Japanese Patent laid-open Publication No.10-260509). In case the telescopic is used, however, as the injection mold has a water pipe for rapid resin cooling, the mold is deteriorated and the resin cooling takes time. As a result manufacturing cost is raised.
An object of the present invention is to provide a lens-fitted photo film unit of which a letter or a mark is changeable easily and cheaply.
In order to achieve the above object, the lens-fitted photo film unit of the present invention is provided with a supplement cover, which is attached to the outside of the lens-fitted photo film unit, for covering the letter or the mark to be visible from outside. The letter or the mark is indicated by making irregularities or printing. When the letter or the mark is done on an opaque part of the lens-fitted photo film unit, the letter or the mark is formed on an outside of the opaque part. Meanwhile, when done on a transparent part, the letter or the mark is formed on an outside or an inside of the transparent part. In case an outline of the letter or the mark is represented by groove or protrusion, protrusion or groove is formed on the mold. The groove or protrusion of the letter or the mark on the product is formed in simultaneous with mold forming.
There are a transparent type and an opaque type in the supplement cover. When the letter or the mark originally formed on the lens-fitted photo film unit is used, the transparent type is selected. When another letter or mark is used, the opaque type is selected.
According to the preferred embodiment of the present invention, either a first outer label or a second outer label is selected, and either of them is attached to the unit body. The first outer label has an opening which exposes the letter or the mark of the lens-fitted photo film unit so as to be visible. The second outer label covers the letter or the mark so as to be invisible. There forms another letter or mark on this second outer label.
According to the present invention, the letter or the mark of the lens-fitted photo film unit is made visible or invisible by selecting either the transparent type or the opaque type in the supplement cover, or by selecting either the outer label with opening or the outer label without opening. The letter or the mark can be easily and cheaply changed by use of the supplement cover or the outer label having different letter or mark thereon. Moreover, it is convenient in that the unit body can be commonly made use of.